The servomotor has become the basic element when it comes to mounting any electronic circuit in which an electric motor is required. The servo motor combines a mechanical part with a digital one. The latter is capable of better processing the signal and offering better results in any servo application.
When the first machines were invented, based on the steam technology developed by James Watt, they offered considerable simplicity. However, today, the movement of motors, shafts and other parts of the motors requires considerable control. Something essential, since in many of its applications it is not only the rotation of the axes that matters, but also their rhythm and the way in which said movement is carried out.
For this reason, it is common for us to find all kinds of servomotors in our environment today. Unlike motors managed by digital converters, servos have a greater control capacity, better manage the speed of rotation and allow control of the position in which the axis rotates at all times. Something fundamental for those machines in which the rotation and the position of said axis change what the machine is doing, as it can happen in a cutter or in a robot.
Although servo motors are typically used in industrial applications, they can also be used for small DIY tasks and other simple assemblies, such as those that can be run with an Arduino servo motor. Something that shows that these servomotors are just as scalable as conventional motors. Therefore, we are going to analyze what this device consists of, to give you all the information you need to handle it.
What is a servomotor
A servomotor, also called a servo or servo motor, is a drive device that is responsible for starting, stopping and regulating the movement in all types of electromechanical projects. Inside it is an encoder, which is the key to its success. This element has the ability to convert the mechanical movement of the motor and the turns it performs into digital pulses. These pulses are interpreted by a motion controller, which generates a clearer signal and a better knowledge of what is happening at all times.
On the other hand, the servomotor incorporates a driver or wheel, with which it is possible to control both the position and the torque of the motor and the speed at which the motor shaft rotates. A complete approach that offers greater efficiency than other similar elements, such as frequency converters. In addition, servo motors work in all types of devices and speeds , while converters are not always suitable in circuits with a low speed of movement or displacement.
How a servo motor works
Once we have the structure and the elements that are part of the servomotor, it is time to know how it works. The first thing we come across in the servo motor approach is a pulse width to voltage converter. This is responsible for receiving energy and converting it from pulses to volts, thus improving control.
On the other hand, we also find a mechanical coupling and a motor system, with which the movement is going to be generated. This element is accompanied by a potentiometer , connected to the central axis of the motor and which allows knowing the angle at which the axis of the motor is located. Something fundamental in applications where position matters, as in certain complex machines. In fact, the industrial servo motor is a great solution to gain control and precision.
Both the potentiometer and the converter generate a signal that goes to the comparator. In this element, the entire operation of the device is controlled and it is verified that it performs as it should, taking into account aspects such as the angle of the shaft, the speed of rotation or the power set by the operator. These elements are connected to the control panel of the servomotor, which is where we will control the operating speed of the device .
This signal travels to the motor and restarts the process again, in case of variation, or maintains system monitoring, if there have been no changes. This is the key to the servomotor and its operation: to always keep the movement and the input voltage controlled and in line through a highly efficient digital system.
For the control of the servo motor, so-called pulses are used. With each pulse that is produced, the motor shaft reproduces a specific movement and changes position, according to the configuration we have established. These pulses are also adjustable, so that the motor has a higher or lower speed. All this process is carried out by means of an electronic board, which makes it easier for the operator to establish the work pulses and rhythms that he may need.
Types of Servomotors
To close our article, we are going to know some of the most common servo motors on the market. All of them come in different sizes, powers and capacities, so whether you are looking for small Arduino servo motors or you need large and powerful models, you can find them in the types that we discuss below.
Direct current servo motor : These servo motors are the most common. They work with direct current and are managed by a pulse width modulation system, which follows the pattern of steps that we have discussed previously.
Alternating current servo motor: Its approach is similar to that of direct current, although in this case the power supply changes. Since alternating current can be more powerful than direct current, these models are used to move heavier loads or for tasks that require more driving force.
Permanent magnet servo motor : These servos change their basic operation, eliminating the usual brushes in alternating current motors. That is why they are called brushless. Its approach is based on synchronous motors and they are capable of supporting high powers and speeds. Therefore, they are the most common in industrial applications.
Stepper servo motor : This device does not follow the full rotation approach of a conventional motor, but rather each pulse generates a step, a certain variable angle of rotation according to the configuration established by the operator. They are the most interesting for tasks that require high precision and exact control of movement.